[Cardiogenic shock and biventricular thrombi as a rare presentation of thyrotoxic cardiomyopathy: a case report].

Thyrotoxic cardiomyopathy is a rare but dreaded form of dilated cardiomyopathy. Its prompt diagnosis is crucial, not only due to the elevated risk of cardiovascular events and mortality, but also because cardiac function may fully recover once a euthyroid state is achieved. Furthermore, thyrotoxicosis is associated with a hypercoagulable state, known to increase the risk of thrombotic events regardless of the CHA2DS2-VA score. However, identification of intracardiac biventricular thrombi is an exceedingly rare presentation. We report the case of a 50-year-old woman, who had previously undergone total thyroidectomy, who presented to the emergency department with acute heart failure (INTERMACS 3). Echocardiography revealed a severely dilated left ventricle and a reduced ejection fraction with biventricular thrombi, further complicated by pulmonary thromboembolism. Investigation revealed an undiagnosed recurrence of intrathoracic goiter which, in addition to ongoing levothyroxine supplementation, led to the development of a thyrotoxic cardiomyopathy. Following the excision of the remaining thyroid tissue, she evolved with complete recovery of cardiac function. This case illustrates a unique presentation of a rare disease, highlighting the importance of keeping in mind etiologic causes that might initially be ruled out.